SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfb995c03f7fbd22b531a9989b6e7995f56cc6f3f9060b576d1a8a4feb1c315a' 
  AND token = 'lX4V14b4K/jdiSKhl8KNxqrxkoBLwIpxHg1fgpWSv5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}